In a typical magnetic storage system, digital data is stored in a series of concentric circular tracks along a storage medium. Data is written to the medium by positioning a read/write head assembly over the medium at a selected location as the storage medium is rotated, and subsequently passing a modulated electric current through the head assembly such that a corresponding magnetic flux pattern is induced in the storage medium. To retrieve the stored data, the head assembly is positioned anew over the track as the storage medium is rotated. In this position, the previously stored magnetic flux pattern induces a current in the head assembly that can be converted to the previously recorded digital data.
Flawscan is a typically a factory process to detect defects on the surface of a magnetic storage medium. A signal is written to the disk and is read back and analyzed by an analog read channel system to detect flaws, based on the amplitude of the signal as it is read back.